The invention relates to a device which allows to preferably explain and demonstrate three-dimensional objects, e.g. anatomical models or even models and exhibits for museums and fairs.
In the field of medical training or in medical demonstrations anatomical models of plastic material or other materials are frequently used. For the explanation or accentuation of certain anatomical areas it is often advisable to mark the relative areas by inscriptions or coloured signs.
The problem with regard to such models is that for the reason of lack of space the information to be imparted by means of an inscription must not be very voluminous. In many cases the inscription is completely omitted, as, for example, the texture of the model (colouring, fine vessels, nerves etc., are to remain recognizable. Therefore the names and informative details belonging to the individual areas of a model are listed on a sheet of paper. The assignment follows from numbers indicated on the model, or from sketches or photos which show the relative areas of the model. Therefore the identification of the model areas of interest is often very complicated and unclear.
The same problems apply to the construction of three-dimensional demonstration models shown in museums or at fairs, in which cases—contrary to medical models—even original objects, such as an oldtimer vehicle in an automobile museum, may be concerned.
Regarding these museum and fair models it may also be advisable to make inscriptions or coloured marks for illustrating, describing or accentuating certain areas or elements of the model. For this purpose electrical switches are often used which—after being touched on the model or away from it—ensure that a certain area of the model becomes visible by means of small incandescent lamps or is explained by means of an inscription lighted up. So-called touchpads are used for special applications allowing the detection of a flat force distribution on the basis of sensing elements arranged in a matrix array, please see also DE 36 42 088 C2. The disadvantage of such arrangements is that there are sensor components between the touched model and the operator so that the original contact properties, such as surface condition, shape and colour, are distorted. Furthermore, owing to the mounting of the sensor components the model to be touched has to be processed. As a result the model may be changed or even damaged. Further, in order to achieve a sufficient level of space resolution over the whole of the concerned model area, a plurality of sensors sensitive to pressure have to be used.
These disadvantages are partly removed by the usage of so-called navigation or tracking systems which detect the contact point not on the side of the model but on the side of the operator, e.g. by tracking the operator's finger or instrument. The range of equipment required for the detection of the operator's movement, however, is excessive.